DELAYING LASH CROSSING FOR A MODULAR HYBRID TRANSMISSION

• US 20150274148A1
• Filed: 03/27/2014
• Published: 10/01/2015
• Est. Priority Date: 03/27/2014
• Status: Active Grant

• Current Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Original Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Inventors: Kraska, Marvin P., Riedle, Bradley D., Reed, Dennis C., Nefcy, Berndard D.
• Granted Patent: US 9,694,804 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: B60W 10/06 including control of combustion engines
• CPC Class Codes: B60W 10/08 including control of electric propulsion units, e.g. motors or generators
• CPC Class Codes: B60W 10/196 acting within the driveline, e.g. retarders
• CPC Class Codes: B60W 10/30 including control of auxiliary equipment, e.g. air-conditioning compressors or oil pumps
• CPC Class Codes: B60W 20/10 Controlling the power contribution of each of the prime movers to meet required power demand
• CPC Class Codes: B60W 2510/06 Combustion engines, Gas turbines
• CPC Class Codes: B60W 2510/08 Electric propulsion units
• CPC Class Codes: B60W 2510/18 Braking system
• CPC Class Codes: B60W 2710/065 Idle condition
• CPC Class Codes: B60W 2710/081 Speed
• CPC Class Codes: B60W 2710/083 Torque
• CPC Class Codes: B60W 30/1884 Avoiding stall or overspeed of the engine
• CPC Class Codes: Y02T 10/62 Hybrid vehicles

Abstract

A method of controlling lash crossing in a hybrid electric automotive powertrain. During deceleration while the powertrain is operating in electric only mode, an input is slowed to a first speed lower than an idle speed of an internal combustion engine. Lash crossing is delayed until the input has slowed to the first speed. When the first speed is zero, lash crossing is delayed until receipt of an acceleration request.

Claims

1. A method of controlling an electrified vehicle powertrain comprising:

producing a first torque in an unpowered electric machine by rotating an input of the machine;

using the machine for regenerative braking to slow the input below an engine idle speed to a non-zero desired input speed;

powering the machine at the desired speed to produce a second torque, opposite the first torque, and lash cross the input.

2. The method of claim 1 wherein the machine receiving the first torque charges a battery and the machine producing the second torque discharges the battery.

3. The method of claim 1 wherein the desired speed is a minimum speed to power a transmission pump.

4. The method of claim 1 wherein the input is disengaged from an engine in the powertrain.

5. The method of claim 1 wherein, prior to the desired speed being reached, powering the machine to produce the second torque and lash crossing the input based upon an acceleration request.

6. A method of controlling an electrified vehicle powertrain comprising:

producing a first torque in an unpowered electric machine by rotating an input of the machine;

using the machine for regenerative braking to slow the input below an engine idle speed to a non-zero desired input speed;

powering the machine when the desired speed is reached to produce a second torque, opposite the first torque, and lash cross the input.

7. The method of claim 6 wherein the first torque charges a battery and the second torque discharges the battery.

8. The method of claim 6 wherein the desired speed is a minimum speed to power a transmission pump.

9. The method of claim 6 wherein the desired speed is zero.

10. The method of claim 6 wherein the input is disengaged from an engine in the powertrain.

11. The method of claim 6 wherein, prior to the desired speed being reached, powering the machine to produce the second torque and lash crossing the input based upon an acceleration request.

12. A method of controlling an electrified vehicle powertrain comprising:

charging a battery of an automotive powertrain by rotating an input to produce a first torque in an unpowered electric machine;

slowing rotation of the input below an engine idle speed to a target speed;

delaying, until the target speed is reached, powering the machine to produce a second torque, opposite the first torque, and lash crossing the input;

operating the machine at the target speed.

13. The method of claim 12 wherein charging of the battery is increased by delaying lash crossing.

14. The method of claim 12 wherein discharging of the battery is decreased by delaying lash crossing.

15. The method of claim 12 further comprising the step of delaying acceleration of the input from the target speed to the idle speed until a torque request is made.

16. The method of claim 12 wherein the target speed is a minimum speed to power a transmission pump.

17. The method of claim 12 wherein the target speed is zero and the machine is not powered to maintain the target speed.

18. The method of claim 12 wherein, prior to the target speed being reached, powering the machine to produce the second torque and lash crossing the input based upon an acceleration request.